A 5.5 ppm/°C, 4.5-nW wide temperature range sub-threshold CMOS Voltage Reference

A novel complementary to absolute temperature (CTAT) generator-based voltage reference circuit is proposed. The design features a resistor-less, ultra-low-power, sub-1V MOSFET-only sub-threshold voltage reference compatible with digital CMOS processes, ideal for low-power and compact applications. The proposed circuit achieves a reference voltage of 0.581V and utilizes highly linear proportional-to-absolute-temperature (PTAT) and complementary-to-absolute-temperature (CTAT) generators to ensure a low temperature coefficient of just 5.5 ppm/°C across a wide temperature range (-50°C to 150°C). The circuit’s analytical behavior is modeled, and extensive post-layout analog simulations in a 0.18-µm CMOS process validate the design’s performance. It demonstrates excellent line sensitivity of 0.1 %/V across a supply voltage range of 0.8 to 3V and achieves a power supply rejection ratio (PSRR) of -53 dB at 100 Hz. Notably, the circuit occupies an area of only 0.005315 mm² and consumes an ultra-low power of 4.5 nW at 27°C. The compact and efficient design addresses the challenges of achieving stability, scalability, and low power in modern CMOS-based systems.